IMMUNOHEMATOLOGY Flashcards
most significant blood group antigen system for transfusion
the ABO system
what are the primary antigens? found?
A B H
present on RBC membrane
large complex sugar and lipid containing molecules which carry peripheral chains of sugars attached to a backbone that inserts into the membrane
what is the significance of the presence of sugars?
they can present in specific linkage conformations that determine antigenic activities
A B H are produced from what?
common glycolipid/glycoprotein precursor by the action of glycosyl transferases
how many loci controls antigen production?
two gene loci
code for production of the glycosyl transferases
when does antibody production begin?
not until after birth
the antibodies are predominantly?
IgM
IgG
*these bind complement and intravascular hemolysis (IgM)
this is the major antigen, controlled by a single gene locus (locus D-autosomal dominant inheritance)
the D antigen
what does D antigen confer of the Rh system?
Rh positivity, more likely to provoke an antibody than any other RBC antigen
what does D sub u antigen confer of the Rh system?
not every Rh positive cell reacts equally well with every anti D blood grouping serum
its weakly expressed and this type of reactivity is due to variants of the D antigen collectively called D sub u
what are other Rh antigens?
C,c,E,e
Rh antibodies are typically?
what is this disease when immunization occurs with fetal maternal hemorrhage when IgG cross the placenta in Rh negative mother with Rh positive baby and the mom develops anti D antibodies
IgG crosses placenta
IgM
IgA
hemolytic disease of the newborn
this usually follows Rh incompatible pregnancy (rarely due to transfusion)
anti-D antibodies
what is the effect when Rh antibodies characteristically do not bind complement?
extravascular hemolysis which causes delayed hemolytic transfusion reactions
what are the tests for serologic incompatibility?
crossmatching
direct antiglobin test (Comb’s test)
type and screen
type and cross
